1. Field of the Invention
The present invention relates to a chip coil, and more specifically to an improved chip coil so as to prevent electromagnetic interference from scattering.
2. Description of Related Art
With regard to a chip coil for an oscillation circuit of an oscillator, it is a well-known way of preventing electromagnetic interference from scattering to enclose the coil with a sleeve core made of a magnetic material. In this case, the inductance (L) becomes 3.5 to 4 times, that is, more than 0.5 .mu.H/mm.sup.3 T, and the quality factor (Q) becomes more than 100.
However, such chip coils varies in inductance (L) to about 30% depending on the accuracy on the sizes of the parts and the errors in putting the parts together, and consequently it is necessary to provide a variable type of condenser for an oscillation circuit in parallel to such a chip coil. Hence, here comes a problem that the costs of parts and adjustments increase.